Cameras, including both video and still cameras, have become more and more ubiquitous to meet increasing demands for recording images for varied purposes such as surveillance, generating business records, or for pleasure. As cameras are used for additional and more varied purposes, there is increased need for cameras that are less expensive, physically smaller, or have improved functionality. The lens of the camera is often one of the most expensive and integral parts of the entire camera, making reductions in its cost or size impact the cost and size of the camera as a whole. Lower-cost or reduced size cameras may be particularly suitable for applications like webcams, mobile phones, or other consumer devices where the desire to reduce costs and size is intensified. Similarly, projectors also utilize lenses to assist in projecting an image on a screen or other surface. As business presentations and other projector uses continue to increase, the need for lower cost or smaller projection lenses (and projectors) also increases.
Inexpensive lenses used in cameras and projectors typically have fixed focus in order to reduce costs, limiting their usability. More expensive cameras such as digital single-lens-reflex (DSLR) camera may have variable focus lenses and sophisticated autofocus systems that move the optical lens or lens elements to achieve proper focus. While variable focus lenses provide a valuable addition to the functionality of lenses, they may have significant drawbacks. Besides the expense of these autofocus systems, they are also subject to failure because of the moving parts. Moreover, traditional autofocus systems also generate some level of noise when focusing the lens, often making them undesirable for surveillance imaging systems where a low profile is advantageous. Reducing the cost and complexity of variable focus lenses, as well as improving their performance, may increase the applications for which variable focus lenses are suitable.